Perhaps the most remarkable feature of yesterday’s Mw=7.9 mainshock was the occurrence of a M=5.6 earthquake 180 km (110 mi) to the southwest of the mainshock, just 15 minutes after the mainshock struck.

The Christmas quake was extremely fast out of the gate, but ran out of gas within 8 seconds, coasting to a stop just 10 seconds later. This saved Chile from suffering a giant quake, but is nevertheless troubling news for Earthquake Early Warning systems.

According to year-end data from the Oklahoma Corporation Commission, there was a 23% drop from 2015 to 2016 in the amount of wastewater injected into the region’s areas of interest for triggered seismicity.

Thursday’s M=6.5 earthquake should have increased the stress on the Mendocino Fault Zone west and east of the rupture zone. These stress increases nominally would have the potential to trigger more earthquakes.

A M=5.5 shock preceded the M=6.1 earthquake by little over 2 hours, and so might be deemed a foreshock. After the Amatrice earthquake, the INGV posted a calculation of the stress transferred from the M=6.2 to surrounding faults.

It’s been over four months since we wrote about the powerful Kumamoto quake sequence: The 15 April 2016 Mw=6.2 (Mjma 6.5) Kumamoto, Japan, shock, which was succeeded 28 hours later by the very damaging Mw=7.0 (Mjma 7.3) shock on the same fault system. We can now give you a preview of crucial new discoveries by Japanese and other researchers.

At 4:37 am Friday morning, a M=7.1 earthquake struck off the east coast of New Zealand, 166 km northeast of Gisborne. This was a moderately deep quake, occurring about 20 km below Earth’s surface, and it caused moderate to strong shaking on land.

Last week’s M=6.2 Italy earthquake left many parts of the medieval city of Amatrice in ruin. In the old part of the city, most buildings were made of unreinforced masonry, leaving them susceptible to collapse [Guidoboni and Valensise, 2015]. Amatrice was all but destroyed in three large shocks over 19 days in 1703, and so the part of the town that was highly damaged on 24 August 2016 was composed of buildings largely constructed about 300 years ago. In contrast, the newer construction in the east side of the town came through the M=6.2 quake relatively unscathed.

The M=6.2 Italy earthquake dominated the seismic headlines today, but an even larger quake just a few hours later was largely ignored. While unrelated, both earthquakes are important. Today’s magnitude 6.8 earthquake struck western Burma, 200 km northwest of the capital city of Naypyitaw.

Today’s earthquake, 10 km southeast of Norcia, has a shallow depth of 10 km, and lies in the Central Apennines normal faulting system. It was felt from Rome to Bologna. One can see from the Temblor map that quakes of this size are expected one or two times in a lifetime at Norcia.